Chapter 4-Tissues

Tissues are?

a group of cells that work together to fucntion

Tissues in combination form?

organs like the heart or lives

Organs can be grouped into how many organ systems?

11

Four types of tissues are?

Epithelial, connective, muscle, neural

Epithelial Tissue does what?

Covers exposed surfaces, lines internal passageways, forms glands

Connective Tissue does what?

Fills internal spaces, transports materials, stores energy

Muscle Tissue does what?

Specialized for contraction, skeletal muscle, heart muscle, and walls of hollow organs

Neural Tissue does what?

Carries electrical signals from one part of the body to another (responds to stimulli

Epithelia Tissue:

Layers of cells covering internal or external surfaces

Glands:

Structures that produce secretions

Characteristics of Epithelia

Cellularity (1 cell next to another)

Polarity (apical and basal surfaces)

Attachment (basement membrane or basal lamina)

Avascularity

Regeneration (scratches)

Functions of Epithelial Tissue

Provide physical protection

Control permeability

Provide sensation

Produce specialized secretions

Classes of Epithelia base on shape:

squamous epithelia

cuboidal epithelia

columnar epithelia

Squamous Epithelia:

thin and flat

Cuboidal Epithelia:

square shaped

Columnar Epithelia:

tall, slender rectangles

Classes of Epithelia based on layers:

Simple epithelium

Stratified epithelium

Simple epithelium:

Single layer of cell

Stratified epithelium

Several layers

Where can Simple Squamous Epithelia be found?

lungs, blood vessels, heart, cornea

In Squamous Epithelium… what is Mesothelium?

Lines the body cavities

In Squamous Epithelium…what is Edothelium?

lines heart and blood vessels

What are some functions of simple squamous epithelium?

reduces friction, controls vessel permeability, performs absorption and secretion

What are some functions of Stratified Squamous Epithelium?

provides physical protection against abrasion, water resistant

Where can Stratified Squamous Epithelium be found?

surface of skin, lining of mouth, throat, esophagus, rectum, anus, and vagina

What are some functions of Simple Cuboidal Epithelium?

limited protection, secretion, absorption

Where can Simple Cuboidal Epithelium be found?

Glands, ducts, portions of kidney tubules, and thyroid

What are some functions of Stratified Cuboidal Epithelium?

Protection, secretion, and absorption

Where can Stratified Cuboidal Epithelium be found

Lining of some ducts (rare)

What are some functions of Transitional Epithelium?

Tolerates repeated cycles of stretching and recoiling and returns to its previous shape without damage.

Appearance changes as stretching occurs.

Situated in regions of the urinary system

Where can Transitional Epithelium be found?

Urinary bladder, renal pelvis, ureters

What are some functions of Simple Columnar Epithelium?

Protection, secretion, absorbtion

Where can Simple Columnar Epithelium be found?

lining of stomach, intestine, gallbladder, uterine tubes, and collecting ducts of kidneys

What are some functions of Pseudostratified columnar epithelium?

Movement comes from cillia, protection, and secretion

Where can Pseudostratified columnar epithelium be found?

Lining of nasal cavity, trachea, and bronchi, and portions of male reproductive tract

What are some functions of Stratified Columnar Epithelium?

Protection

Where can Stratified Columnar Epithelium be found?

Small areas of the pharynx, epiglottis, anus, mammary glands, salivary gland ducts, and urethra

Functions of Connective Tissues:

Establishing a structural framework for the body.

Transporting fluids and dissolved materials.

Protecting delicate organs.

Supporting, surrounding, and interconnecting other types of tissue.

Storing energy reserves, especially in the form of triglycerides.

Defending the body from invading microorganisms.

\

Characteristics of Embryonic Connective Tissue:

Not found in adults

Where is Embryonic Connective Tissue found?

Umbilical cord of a fetus

What is Mucous Connective Tissue?

Loose embryonic connective tissue

What is Mesenchyme Tissue?

The first connective Tissue in embryos

What is Loose Connective Tissue?

The packing materials of the body

What are the three types of Loose Connective Tissue?

Areolar

Adipose

Recticular

Characteristics of Areolar Tissue:

Least specialized.

Open framework.

Viscous ground substance.

Elastic fibers.

Holds blood vessels and capillary beds.

(found under skin).

Characteristics of Adipose Tissue:

Contains many adipocytes (fat cells)

Provides padding and cushion

Where can you find Adipose Tissue:

Deep to the skin, especially in sides, buttocks, breasts, and padding around eyes and kidneys

What are two types of Adipose Tissue?

White fat

Brown fat

Characteristics of White fat:

Avascular.

Most common.

Stores fat.

Absorbs shocks

Slows heat loss.

Protection.

Characteristics of Brown fat:

More Vascularized.

Adipocytes have many Mitochondria.

When stimulated by the nervous system, fat breakdown accelerates releasing energy.

Absorbs energy from surrounding tissues.

Characteristics of Adipose cells:

Adipocytes in adults do not divide.

Expand to store fat.

Shirnk as fats are leased

Characteristics of Reticular Tissue:

Provides support.

Framework

Supportive fibers (stroma)

The Reticular Organs are?

Spleen, liver, lymph nodes, and bone marrow

What is Dense Connective tissue

Connective tissue, tightly packed with high numbers of collagen or elastic fibers

What are some types of Dense Connective tissue?

Dense regular connective tissue.

Dense irregular connective tissue.

Elastic tissue

Functions of Dense Regular Connective Tissue:

Provides form attachment.

Conducts pull of muscles.

Reduces friction between muscles.

Stabilizes relative positions of bones.

Where is Dense Regular Connective Tissue found?

Between skeletal muscles and skeleton (tendons and aponeuroses); between bones or stabilizing positions or internal organs (ligaments covering skeletal muscles).

Functions of Elastic Tissue:

Stabilizes positions of vertebrae and penis; cushions shocks; permits expansion and contraction of organs

What is a Fluid Connective Tissue?

Watery matrix of dissolved proteins

Carry specific cell types

Blood and Lymph

What are three types of Cartilage?

Hyaline Cartilage

Elastic Cartilage

Fibrocartilage

Where is Hyaline Cartilage found?

Between tips of ribs and bones of sternum; covering bone surfaces at synovial joints; su

Functions of Hyaline Cartilage:

somewhat flexible support; reduces friction between boney surfaces

Where is Elastic Cartilage found?

auricle of external ear; epiglottis; auditory canal

Functions of Fibrocartilage:

Prevents bone to bone contact and limits movement

Where can Fibrocartilage be found?

Pads within knee joint, pelvic bones

What is Bone or Osseous Tissue?

strong (calcified calcium salt deposits)

Resists shattering (flexible collagen fibers)

What is Bone cells or Osteocytes?

Arranged around central canals within matrix

small channels through matrix access blood supply

What is Periosteum?

Covers bone surfaces

Fiberous layer

Cellular layer

Function of Muscle Tissue:

specialized for contraction

produces all body movement

What are the three Muscle Tissues?

Skeletal muscle tissue, cardiac muscle tissue, smooth muscle tissue

What is Skeletal Muscle Tissue?

Large body muscles responsible for movement

What is Cardiac Muscle Tissue?

Found only in the heart

What is Smooth Muscle Tissue?

Found in walls of hollow, contracting organs (blood vessels; urinary bladder; respiratory, digestive, and reproductive tracts)

What is a Striated Muscle Cell?

A muscle cell with a banded appearance

What is a Nonstraited Muscle Cell?

A non banded; smooth

What are some characteristics of Muscle Cells?

Muscle cells can have a single nucleus

Muscle cells can be multinucleate

Muscle cells can be controlled voluntarily (consciously)

Muscle cells can be controlled involuntarily (autonatically)

What are some Characteristics of Skeletal Muscle Cells?

Long and thin

Usually called Muscle Fibers

Do not divide

New fibers are produced by stem cells

What are some characteristics of Cardiac Muscle Cells?

Form branching networks connected at intercalated discs

(regulated by pacemaker cells)

Usually with a single nucleus

What are some characteristics of Smooth Muscle Cells?

Small and tapered

Can divide and regenerate

Moves food and urine

Where is Smooth Muscle Tissue found?

Found in the walls of blood vessels and in digestive, respiratory, urinary, and reproductive organs

Characteristics of Neural Tissue?

(Also called nervous or nerve tissue)

Specialized for conducting electrical impulses.

Rapidly sense internal or external environment.

Processes information and controls responses.

Where is the Neural Tissue concentrated?

In the central nervous system

Brain and Spinal Cord

What are the two types of Neural Cells?

Neurons and Neuroglia

(supports eachother)

What are Neurons Cells?

Nerve cells; they perform electrical communication

What are Neuroglia Cells?

Supporting cells

Repair and supply Nutrients to neurons

What are the three cell parts of a Neuron?

Cell body, Dendrites, and the Axon

In the Cell Body of a Neuron what does it do?

Contains nucleus and nucleolus; communicates

In the Dendrites of a Neuron what does it do?

Short branches extending from the cell body; Receive incoming signals

In the Axon of a Neuron what does it do?

Long, thin extension of the cell body; carries outgoing electrical signals to their destination.